Back in 2006, two network operators in Germany who so far only had GSM spectrum in the 1800 MHz range each got assigned a 5 MHz chunk of 900 MHz spectrum to improve rural coverage and urban in-house coverage. Also the move was necessary to equalize the playing field with the other two network operators who already owned 900 MHz spectrum from the beginning. It's 5 years later now so I wondered if and how they have made good use of it.
While I was recently on the countryside in Southern Germany I had a look in a number of places where 900 MHz spectrum would have been very beneficial. While O2 made consistent use of 900 MHz spectrum there in addition to some 1800 MHz carriers, E-Plus only used it very occasionally. I wouldn't have expected that as, after all, it's E-Plus who's always pointing out that they are at such a disadvantage.
The picture is even more interesting in cities. Here, 900 MHz spectrum significantly improves indoor coverage as can be observed with UMTS 2100 coverage being lost indoors much sooner than UMTS. Again, O2 has made use of their 900 MHz spectrum in Cologne in addition to their 1800 MHz spectrum. And again, no traces of a 900 MHz GSM deployment from E-Plus 5 years after they've been awarded spectrum.
On the other hand, their lack of 900 MHz deployment offers some interesting possibilities for UMTS deployment strategies. They've talked about that before in the press but only seeing is believing.